What absorbs at 3289 cm⁻¹ in an FTIR spectrum?
A band near 3289 cm⁻¹ can point to several functional groups. Below are the most likely assignments, ranked by how much published evidence supports each — every one traceable to literature (DOI) and cross-validated against our 130,000+ reference spectra and knowledge graph.
Backed by 8 cited sources
Quick answer
A band near 3289 cm⁻¹ is usually interpreted by checking which functional groups repeatedly co-occur there in the literature, then confirming at least one or two additional peaks in the same sample. This page ranks those assignments by accumulated evidence rather than by a single fixed textbook rule.
Possible functional-group assignments
| Functional group | Supporting facts | Cited sources | Top confidence |
|---|---|---|---|
| Hydroxyl (O-H) | 8 | 8 | 1.0 |
| N h | 5 | 4 | 1.0 |
| Hydrogen bond | 2 | 2 | 1.0 |
| Amide | 2 | 2 | 1.0 |
| Alkyl C-H | 1 | 1 | 1.0 |
| Secondary amine | 1 | 1 | 1.0 |
Ranking reflects accumulated literature evidence, not a single fixed rule. Always confirm against your sample context.
Possible materials
| Material | Supporting peaks | Overlapping groups | Cited sources |
|---|---|---|---|
| chitosan | 3289, 1650, 1655 | Amide, Hydroxyl (O-H), N h | 1 |
| polysaccharides | 3289, 1053, 1143 | Amide, Hydroxyl (O-H) | 1 |
| diamond | 3289, 1378, 1332 | Amide, Hydroxyl (O-H) | 1 |
Materials are shown only when the same literature pool supports this band and at least one additional characteristic peak.
Spectrum logic
This band becomes meaningful only when read with its neighboring peaks. In practice, analysts first look at the assignments above, then check whether the same sample also shows other peaks expected for the same structural motif. A lone band near 3289 cm⁻¹ is usually not enough for material identification by itself.
Real-world usage
This type of query is common in polymer identification, unknown plastic screening, QC troubleshooting, recycled-material verification, and literature-backed peak assignment review.
Common mistakes
- Treating one isolated band as proof of a material without checking at least one or two supporting peaks.
- Ignoring overlap: multiple functional groups can contribute near the same wavenumber.
- Skipping validation when additives, blends, oxidation, or contamination may distort the spectrum.
Verification advice
When ambiguity remains, validate the hypothesis with DSC, GC-MS, or TGA, especially for blends, degraded samples, and filled polymers.
Literature behind these assignments
-
Hydroxyl (O-H) confidence 1.0
“30 peaks at 3288.63 represents for alcoholic group, OH stretch, 2926.01 for carboxylic acid OH 31 32 Accepted stretch, 1597.06 for aliphatic nitro compounds, and 1379.10 for organic sulfates in the region of 33”
Kalpana 和 Rajeswari - 2018 - Synthesis of palladium nanoparticles via a green r DOI: 10.1088/2053-1591/aaddef -
Amide confidence 1.0
“The amide A band centered around cm-1 3289 is fairly broad due to the stretching of the nitrogen and hydrogen bond of the amide.”
Design and Development of a Bimodal Optical Instrument for Simultaneous Vibrational Spectroscopy Measurements DOI: 10.3390/ijms23126834 -
N h confidence 1.0
“The band cm-1 cm-1 at 3289 is characteristic of NH and OH stretching vibrations.”
Durazzo 等 - 2018 - Qualitative Analysis of Traditional Italian Dishes DOI: 10.3390/su10114112 -
Hydroxyl (O-H) confidence 1.0
“The bands observed at 3289 cm-1 cm-1 and 2873 were determined by the -OH stretching and C-H aliphatic stretching,”
Physicochemical Properties and Functional Characteristics of Ecologically Extracted Shrimp Chitosans with Different Organic Acids during Demineralization Step DOI: 10.3390/molecules27238285 -
Hydroxyl (O-H) confidence 1.0
“3550-3200 O-H stretch Alcohol 3288.55 3288.48 3381.70”
The Authentication and Grading of Edible Bird’s Nest by Metabolite, Nutritional, and Mineral Profiling DOI: 10.3390/foods10071574 -
Amide confidence 1.0
“spectrum, (NH) band was shifted by 5 unit to the higher wavenumbers and appears at cm-1, cm-1, amide I band, 3289 (C=O), which occurs at 1648 was shifted by 10 units to lower wavenumbers, compared to same bands in NIPAM spectrum, which is c”
Ilic-Stojanovic 等 - 2018 - Thermosensitive hydrogels for modified release of DOI: 10.1080/00914037.2017.1354202 -
Hydroxyl (O-H) confidence 1.0
“For all samples, peaks between 3289 and 3316 were observed, 2 which relate to the stretching of hydroxyl (OH) groups due to the formation of hydrogen bonds [50].”
Encapsulation of Concentrated Solution Obtained by Block Freeze Concentration in Calcium Alginate and Corn Starch Calcium Alginate Hydrogel Beads DOI: 10.3390/gels9050374 -
Hydroxyl (O-H) confidence 1.0
“(Figure 6a) shows a peak at 3289 which is ascribed to the extensive intramolecular hydrogen cm-1 bonds and stretching vibration of the -OH groups [12,14,17,18].”
Guar Gum as an Eco-Friendly Corrosion Inhibitor for Pure Aluminium in 1-M HCl Solution DOI: 10.3390/ma12162620
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